Facts didn't matter in 1992: A shopping center burning after riots broke out in Los Angeles, following the acquittal of the four cops accused of beating Rodney King.Getty Images

Some of us, who are old enough to remember the old TV police series “Dragnet,” may remember Sgt. Joe Friday saying, “Just the facts, ma’am.” But that would be completely out of place today.

Facts are becoming obsolete, as recent events have demonstrated.

What matters today is how well you can concoct a story that fits people’s preconceptions and arouses their emotions.

Politicians like Mayor de Blasio, professional demagogues like Al Sharpton and innumerable irresponsible people in the media have shown that they have great talent in promoting a lynch mob atmosphere toward the police.

Grand juries that examine hard facts live in a different world from mobs who listen to rhetoric and politicians who cater to the mobs.

During the controversy over the death of Trayvon Martin, for example, a member of the Congressional Black Caucus said that George Zimmerman had tracked Trayvon Martin down and shot him like a dog. The fact is that Zimmerman didn’t have to track down Trayvon Martin, who was sitting right on top of him, punching him till his face was bloody.

After the death of Michael Brown, members of the Congressional Black Caucus stood up in Congress, with their hands held up, saying “Don’t shoot.” Although there were some who claimed that this is what Michael Brown said and did, there were other witnesses — all black, by the way — who said that Brown was charging toward the policeman when he was shot.

What was decisive wasn’t what either set of witnesses said, but what the autopsy revealed, an autopsy involving three sets of forensic experts, including one representing Brown’s family.

Witnesses can lie but the physical facts don’t lie, even if politicians, mobs and the media prefer to take lies seriously.

The death of Eric Garner has likewise spawned stories having little relationship to facts. The story is that Garner died because a chokehold stopped his breathing. But Garner didn’t die with a policeman choking him.

He died later, in an ambulance where his heart stopped. He had a long medical history of various diseases, as well as a long criminal history.

No doubt the stress of his capture didn’t do him any good, and he might well still be alive if he hadn’t resisted arrest. But that was his choice.

Despite people who say blithely that the police need more “training,” there is no “kinder and gentler” way to capture a 350-pound man, who is capable of inflicting grievous harm, and perhaps even death, on any of his would-be captors.

The magic word “unarmed” means nothing in practice, however much the word may hype emotions.

If you’re killed by an unarmed man, you are just as dead as if you had been annihilated by a nuclear bomb. But you don’t even know who is armed or unarmed until after it’s all over, and you can search him.

Incidentally, did you know that, during this same period when riots, looting and arson have been raging, a black policeman in Alabama shot and killed an unarmed white teenager — and was cleared by a grand jury? Probably not, if you depend on the mainstream media for your news.

The media don’t merely ignore facts, they suppress facts.

Millions of people saw the videotape of the beating of Rodney King. But they saw only a fraction of that tape because the media left out the rest, which showed King — another huge man — resisting arrest and refusing to be handcuffed, so that he could be searched.

TV viewers didn’t get to see the other black men in the same vehicle that Rodney King was driving recklessly. Those other black men weren’t beaten. And the grand jurors got to see the whole video, after which they acquitted the police — and the media then published the jurors’ home addresses.

Such media retribution against people they don’t like is part of a growing lynch-mob mentality. The black witnesses in Missouri, whose testimony confirmed what the police officer said, expressed fears for their own safety for telling what the physical evidence showed was the truth.

Is this what we want? Grand juries responding to mobs and the media, instead of to the facts?